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31.
Dechow CD Rogers GW Sander-Nielsen U Klei L Lawlor TJ Clay JS Freeman AE Abdel-Azim G Kuck A Schnell S 《Journal of dairy science》2004,87(10):3526-3533
The objectives of this study were to estimate genetic correlations among body condition scores (BCS) from various sources, dairy form, and measures of cow health. Body condition score and dairy form evaluated during routine type appraisal was obtained from the Holstein Association USA, Inc. A second set of BCS was obtained from Dairy Records Managements Systems (DRMS) and was recorded by producers that use PCDART dairy management software. Disease observations were obtained from recorded veterinarian treatments in several dairy herds in the United States. Estimated breeding values for diseases in Denmark were also obtained. Genetic correlations among BCS, dairy form, and cow health traits in the United States were generated with sire models. Models included fixed effects for age, DIM, and contemporary group. Random effects included sire, permanent environment, herd-year season for health traits, and error. Predicted transmitting abilities (PTA) for BCS and dairy form were correlated with estimated breeding values for disease in Denmark. The genetic correlation estimate between BCS from DRMS and BCS from the Holstein Association USA, Inc., was 0.85. The genetic correlation estimate between BCS and a composite of all diseases in the United States was -0.79, and PTA for BCS was favorably correlated with an index of resistance to disease other than mastitis in Denmark (0.27). Dairy form was positively correlated with a composite of all diseases in the United States (0.85) and was unfavorably correlated with an index for resistance to disease other than mastitis in Denmark (-0.29). Adjustment for protein yield PTA had a minimal affect on correlations between PTA for BCS or dairy form and disease in Denmark. Selection for higher body condition or lower dairy form with continued selection for yield may slow deterioration in cow health as a correlated response to selection for increased yield. 相似文献
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33.
Effect of potassic and phosphatic fertilizer type, fertilizer Cd concentration and zinc rate on cadmium uptake by potatoes 总被引:6,自引:0,他引:6
M. J. McLaughlin N. A. Maier K. Freeman K. G. Tiller C. M. J. Williams M. K. Smart 《Nutrient Cycling in Agroecosystems》1995,40(1):63-70
In some areas of southern Australia, cadmium (Cd) concentrations in excess of the Australian maximum permitted concentration (0.05 mg kg–1 fresh weight) have been found in tubers of commercially grown potato (Solanum tuberosum L.) crops. Field experiments were therefore conducted in various regions of Australia to determine if Cd uptake by potatoes could be minimised by changes in either phosphorus (P), potassium (K) or zinc (Zn) fertilizer management.Changing the chemical form in which either P fertilizer (monoammonium phosphate, diammonium phosphate, single superphosphate and reactive rock phosphate) or K fertilizer (potassium chloride and potassium sulfate) were added to crops had little influence on tuber Cd concentrations. Fertilizer Cd concentrations also had little influence on tuber Cd concentrations, suggesting that residual Cd in the soil was a major contributor to Cd uptake by the crops on these soils.Addition of Zn at planting (up to 100 kg Zn ha–1) significantly reduced tuber Cd concentrations at four of the five sites studied. However, the largest variation was between sites rather than between treatments, with site mean tuber Cd concentrations varying tenfold (from 0.018 to 0.177 mg Cd kg–1 fresh weight). Factors associated with irrigation water quality at the sites, in particular the chloride concentration, appeared to dominate any effects of changing fertilizer type or Cd concentration. 相似文献
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35.
The purpose of this study was to develop regression equations to predict manual arm strength for a wide variety of hand locations within the reach envelope. Maximum voluntary manual arm strength was determined from 71 female participants in six exertion directions (superior, inferior, anterior, posterior, medial and lateral), in a total of 28 hand locations. Forces ranged from 51.3 to 164.4 N, and had a pooled coefficient of variation of 29.9%. Across all 168 combinations of hand locations and exertion directions, the multivariate regression equations explained 92.5% of the variance and had a root mean square error (RMSE) of only 6.4 N, using only the anterior, lateral and vertical location of the hand relative to the active shoulder joint as inputs. These equations provide a proof-of-principle for our novel regression approach, and represent a first step towards a more comprehensive equation to estimate maximum acceptable forces for occupational tasks. 相似文献
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Cora-Costanze Sommerey Tim L. WilliamsIan McCrone Aran Ruiz-FerrerasDan Freeman Joy Archer 《Journal of dairy science》2014
Thromboelastography is a whole blood-based coagulation assay that can be used to investigate hypocoagulability and hypercoagulability, as seen with thromboembolic diseases and disseminated intravascular coagulation. Numerous coagulopathies due to different causes are reported in cows. The objective was to establish reference intervals for thromboelastography using the TEG 5000 (Haemonetics GmbH, Munich, Germany) with citrated whole blood samples and kaolin activation in dairy cows and to investigate possible thromboelastographic changes between cows in different lactation periods. An additional objective was to test the stability of samples for up to 100 h. Sixty blood samples from healthy Holstein-Friesian cows were examined. The samples were allocated to 3 different lactation groups (≤30 d postcalving, 31–99 d postcalving, ≥100 d postcalving). Thromboelastography was performed by using the TEG 5000 analyzer with citrated whole blood samples with kaolin activation. The calculated reference intervals were as follows: reaction time = 2.2 to 6.2 min, coagulation time = 0.8 to 2.0 min, angle α = 58.2 to 81.8°, maximum amplitude = 64.3 to 89.2 mm, and clot rigidity = 9.2 to 41.2 dyn/cm2. The 3 different lactation groups showed no significant differences in TEG parameters. No significant difference was seen in samples stored for up to 48 h at room temperature, which indicates that delays in processing samples, such as those arising during transit, are not an issue. 相似文献
38.
Ronald E. Davis Dallas G. Denery David A. Kendrick Raman K. Mehra 《Computational Economics》2012,39(1):71-76
A continuous-time control model was formulated and fitted to macroeconomic data by an expert control engineer who worked at
NASA-AMES in the 1980s, Rodney C. Wingrove. Two articles were prepared and made available to the aerospace industry at that
time, however the authors feel that wider distribution of his study posthumously is warranted at this time. This introduction
to the two Wingrove articles that follow provides background information on the technologies Wingrove was working with, as
well as subsequent developments in both macroeconomic and engineering modeling and analysis technology. Our purpose is to
stimulate further research along the same lines which can potentially lead to structural and/or policy rule improvements that
can prevent the extremely turbulent abberations that have been seen in recent years, and promote steady growth with low inflation
and low unemployment in a sustainable way. Of particular concern is the exploding national debt problem. 相似文献
39.
Vouchers have come to be seen as a tool for promoting economic and racial/ethnic integration. Discrimination based on Source of Income (SOI), however, could hinder the use of vouchers to move to more desirable neighborhoods. State and local SOI anti-discrimination laws (SOI laws) are one policy response to address this issue. SOI laws make it illegal for landlords to discriminate against voucher recipients solely on the basis of their having a voucher. The research presented here tested whether SOI laws in the USA improve locational outcomes for voucher recipients. This research found that the impacts of SOI laws on locational outcomes are mixed. We found substantively important reductions in neighborhood poverty rates associated with the implementation of SOI laws and small but statistically significant reductions in minority concentration as well. The concentration of voucher recipients in a neighborhood, however, does not appear to be related to SOI law implementation. 相似文献
40.
让周遭的系统能够自动感测环境变化并做出反应,势必将对于人类的生活造成重大改变。无线传感器网络是多个分布式传感器实作(节点)组成的系统,能够共同透过相互无线通信的方式响应实体变化。本文将重点介绍节点的最新进展,并推广对于系统层级设计方法的需求。 相似文献